Wash-over spear apparatus



Aug. 29, 1961 Filed June 12, 1957 w. F. CAROTHERS WASH-OVER SPEAR APPARATUS 2 Sheets-Sheet 1 2 INVENTOR William F.Corothers Fig. 2

ATTORNEY United States Patent Filed June 12, 1957, Ser. No. 665,629 1 Claim. (Cl. 166-237) This invention relates to new and useful improvements in wash over spear apparatus.

An object of this invention is to provide a wash over spear apparatus for freeing a stuck pipe in a well bore, wherein after the stuck pipe is freed, it is prevented from falling in the well bore a suflicient distance to cause buckling or other damage to the stuck pipe or the pipe connected therebelow.

An important object is to provide an improved apparatus wherein a retrieving assembly is combined with a wash pipe in such manner that the wash pipe may be utilized to connect the retrieving assembly to a stuck pipe, after which said wash pipe may thereafter be employed in the usual manner to wash over the stuck pipe to effect its release; said apparatus including means for connecting the wash pipe and the retrieving assembly after the stuck pipe has been released, whereby said pipe may be retrieved with removal of the wash pipe from the well bore.

A particular object is to provide a wash-over spear apparatus having a wash pipe within which a retrieving assembly is adapted to be disposed, together with anchoring means forming part of said retrieving assembly and automatically operable to anchor the retrieving assembly within the pipe in the event the stuck well pipe being washed over suddenly falls downwardly during the washover operation whereby dropping of the well pipe due to release by said wash-over operation is prevented.

Another object is to provide an apparatus, of the character described, wherein the retrieving assembly may be selectively disconnected and reconnected-from the washpipe after the parts have been lowered into the well bore, which arrangement permits the wash pipe to be employed to first connect the retrieving assembly to the stuck pipe, then to function independently of the retrieving assembly while washing over the pipe and to thereafter, following loosening of the stuck pipe, to be re-connected with the retrieving assembly to be utilized in withdrawing the loosened pipe from the-well bore. 1

A further object is to provide an apparatus, of the character described, wherein the retrieving assembly includes an anchoring means which, upon operation, connects the assembly to the wash pipe, together with a control means for said anchoring means, which control means is operable by manipulation of the wash pipe; said control means functioning to prevent actuation of the anchoring means when in one position and permitting actuation of said anchoring means when in another position, whereby said anchoring means may be selectively rendered non-settable or settable at the operators will.

The invention will be readily understood by referring to the following description and the accompanying drawing, in which:

FIG. 1 is a fragmentary sectional elevational view, taken on a median line, of wash-over spear apparatus embodying the invention, the parts being shown in the positions which they occupy during the wash-over operation, with the spear connected to the stuck object but released from the wash-over pipe, and the latching mechanism being shown in unlatched position;

FIG. 2 is a view similar to that of FIG. 1, the parts being shown in the positions which they occupy when the spear is anchored to the wash-over pipe;

FIG. 3 is a sectional plan view taken on the lines 3-3 of FIG. 1;

h 2,998,078 Patented Aug. 29, 1961 'ice FIG. 4 is a sectional plan view taken on the lines 4-4 of FIG. 1; and

FIG. 5 is a sectional plan view taken on the lines 55 of FIG. 2.

FIGS. 6 to 9 are detail views showing portions of the apparatus.

Refer-ring to the drawing, the apparatus of the invention includes a wash-over pipe 1, which is adapted to be connected at its upper end to a string of pipe whereby it is suspended from the surface, and which is capable of being lowered in a well bore in which a drill pipe or other object 2 is stuck. A spear mechanism as hereinafter described, capable of engaging the stuck object 2, is located within the wash-over pipe 1.

The spear mechanism of the invention comprises an inner tubular mandrel 3, which is reduced intermediate its ends to form an upwardly facing external shoulder 4, and which is enlarged at 5, adjacent its lower end, to form an upwardly facing external shoulder 6. The lower end of the mandrel 3 is externally threaded, as at 7, for connection to the upper end of the stuck object 2, which may be a packer, liner, drill pipe or drill collar.

The upper end of the mandrel 3 is connected by threads 8 to a pipe nipple 9. The nipple 9 is flanged at its lower end, as at 10. A collar 11, which surrounds the lower end of the nipple 9, is internally enlarged to form a downwardly facing shoulder 12 for engagement with the flange 10, and is connected by threads 13 to the nipple 9. A threaded pin 14 is inserted through aligned openings provided therefor in the collar 111, the nipple 9 and the mandrel 3 whereby they are prevented from being rotated relative to each other.

A plurality of circumferentially spaced holes 15 are provided in the peripheral wall of the collar 111 for engagement by shear pins (not shown) whereby the spear mechanism is temporarily connected to the wash-over pipe 1 while lowering it into the well, and thereafter, while connecting the mandrel 3 to the stuck object 2.

Any suitable type of grappling device may be connected to the threaded lower end of the mandrel 3 when necessary, depending upon the nature of the object which is to be removed from the well.

A friction shoe cage 16, which surrounds the mandrel 3, is positioned immediately above the shoulder 6. The cage 16 may be of a conventional type having external recesses 17- within which friction blocks or shoes 18 are movably' disposed for radial movement relative to the cage 16. The shoes 18 are urged radially outwardly into frictional contact with the interior of the wash-over pipe 1 by resilient elements, such as the coil springs 19, located beneath the shoes 18 in the usual manner.

A slip cage 20, which surrounds the mandrel 3, is connected by threads 21 to the upper end of the friction shoe cage 16. Externally toothed tapered slip elements 22 are connected to the upper end of the slip cage 20, for radial movement relative thereto, by means of a flange 23 and an annular groove 24 formed on the upper end of the slip cage 20 for engagement, respectively, by corresponding grooves 25 and projections 26 formed on the lower ends of the slip elements 22.

The slip elements 22 are formed with slots 27 in their inner faces for sliding, dovetailed engagement with corresponding projections 28 formed on the external surface of a downwardly and inwardly tapered slip actuating member 29. The slip actuating member 29, which surrounds the mandrel 3, is positioned above the shoulder 4. A thrust bearing 30 is positioned between the shoulder 4 and the slip actuating member 29 whereby the slip actuating member 29 and the slip elements 22 are rotatable relative to the mandrel 3. The lower end of the nipple 9 bears against the upper end of the slip actuating member 29 whereby the slip actuating member 29 r j W p M f 3 is prevented from being moved longitudinally relative to the mandrel 3. V i l A pair of J slots 31 are formed in the peripheral surface of. the-mandrel 3, beginning at thetshoulder 4 and extending downwardly therefrom. The slip cage 20 is internally enlarged at 32,adjacent its lower en d'. 'An arcuate member 33, which is formed of spring steel and has inwardly extending. end portions 34 for engagement with the J slots 31, is received in the internally enlarged portion 32 of the slip cage 20. A thrustt bearing 35' is positioned between the arcuate member 33 and a shoulder formed by the upper end of the friction shoe cage '16, and a thrust bearing 36ispositioned between the arcuate member 33 and the inner end of the internally enlarged portion 32 of the slip cage 20.

In operation, the device is lowered into the well bore until the wash-over pipe 1 partially encircles the stuck object 2, and the threaded lower end 7 of the mandrel 3 engages the threaded'upper end of the stuck object 2, which may be a drill pipe, for example. The mandrel 3' is connected to the stuck object 2, and thereafter the pins connecting the wash-over pipe 1 to the collar 11 are sheared by lowering the wash-over pipe 1 relative to the mandrel 3. l

The wash-over pipe, 1 has cutting means (not shown) connected to its lower end for use in cutting away the formation surrounding the stuck object 2.

' If the stuck object 2 should suddenly drop freely in the well bore, downward movement of the mandrel 3 relative to rthe wash-over pipe 1 will result in setting of the slips, whereby the spear mechanism is'anchored to the wash-over pipe 1 and is prevented from dropping in the well boreralong with the object 2.

The spear mechanism is capable of being withdrawn from the well bore, together withthe wash-over pipe 1', upon setting of the slips as above described, whereby the spear mechanism is' anchored to the wash-over pipe 1.

, The arcuate member 33 frictionally engages the inner wall of the slip cage 20 whereby the end portions 34 of the arcuate member 33 are movable into latching position relative to, the J slots 31 upon rotating the washover pipe '1, the friction shoe cage 16 and the slip cage 20, the wash-over pipe 1 first being lowered relative to the mandrel 3 until the arcuate member 33; is positioned opposite the lower ends of the J slots 31. This arrange: ment enables the friction shoe cage 16, the slip cage 20 and the slip elements '22 to be anchored to the mandrel 3 to prevent movement of the slip elements 22 relative to the slip actuating member 29, to set the slips.

The arrangement above described permits the washover pipe 1 to be raised in the'well bore, independently of the spear mechanism, without engaging the slips.

The invention may be modified in various ways without departing from the spirit "and scope thereof.

A wash over spear apparatus comprising, in combination with awash pipe; a mandrel arranged concentrically and coaxially within the wash pipe, the mandrel having an enlarged, externally threaded lower end portion engageable with a stuck object, a friction shoe cage and a slip cage surrounding the mandrel, above its enlarged lower end portion, and movable longitudinally and rotatively relative thereto, the friction shoe cage and the slip cage being connected end to end and positioned one above the other with the slip cage uppermost, pipe gripping slips engageable with the inner wall of the wash pipe loosely connected at their lower ends to the slip cage, a tapered element surrounding the mandrel, above the slips, coacting with the slips to expand them radially outwardly upon advancing it longitudinally relative thereto, the tapered element being movable longitudinally with the mandrel while at the same time being movable rot-atively with the slips, friction shoes on the friction shoe cage engageable with the inner wall of the wash pipe, the mandrel having an upwardly facing external shoulder below the tapered element and an abutment above the tapered element securing the tapered element against longitudinal displacement relative thereto, the mandrel having a pair of circumferentially spaced J slots in its peripheral surface extending downwardly from the shoulder, the slip cage being interna-lly enlarged, and an arcuate member, formed of spring steel, received in the internally enlarged portion of the slip cage and frictionally engaging the inner wall thereof whereby the arcuate member is movable rotatively with the slip cage, the arcuate member having radially inwardly extending end portions received in the J slots whereby theslip cage is adapted to be releasably anchored to the mandrel by rotative movement of the arcuate member, with the slip cage, relative to the mandrel after first lowering the slip cage to a position in which the end portions of the arcuate member are positioned oppositethe widened lower ends of the J slots.

References Cited inthe file of this patent STATES PATENTS 

